1. Cancer Epidemiology Group, University of Leeds, Leeds, United Kingdom.
2. Medical Oncology, St. James's Institute of Oncology, Leeds, United Kingdom.
3. Teenage Cancer Trust Unit, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
4. Alder Hey Children's NHS Foundation Trust, Liverpool, United Kingdom.
5. Leeds Institute of Health Sciences, University of Leeds, Leeds, United Kingdom.
6. Paediatric Epidemiology Group, University of Leeds, Leeds, United Kingdom.